Abstract Glaucoma is a highly heritable disease, and myocilin was the first identified causal and most common pathogenic gene in glaucoma. Serine-to-proline mutation at position 341 of myocilin (MYOC S341P ) is associated with severe glaucoma phenotypes in a five-generation primary open-angle glaucoma family. However, the underlying mechanisms are underexplored. Herein, we established the MYOC S341P transgenic mouse model and characterized the glaucoma phenotypes. Further, we systematically explored the functional differences between wild-type and MYOC S341P through immunoprecipitation, mass spectrometry, and RNA-seq analyses. We found that MYOC S341P transgenic mice exhibit glaucoma phenotypes, characterized by reduced aqueous humor outflow, elevated intraocular pressure, decreased trabecular meshwork (TM) cell number, narrowed Schlemm’s canal, retinal ganglion cell loss, and visual impairment. Mechanistically, the secretion of dysfunctional MYOC S341P accumulated in the endoplasmic reticulum (ER), inducing ER stress and dysregulation of autophagy, thereby promoting TM cell death. We describe an effective transgenic model for mechanistic studies and the screening of therapeutic targets. Our data generated from high-throughput analyses help elucidate the mechanism underlying mutant MYOC-related glaucoma.
Purpose: The clinical characteristics and prognoses of immunoglobulin G4-positive (IgG4+) and IgG4-negative (IgG4−) lacrimal lymphomas were comparatively analyzed to screen for clinical indicators with differential diagnostic significance. Methods: This was a retrospective and single-center clinical study. From June 2011 to June 2018, clinical data of 39 patients with lacrimal lymphoma, diagnosed by histopathology were collected from the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University. Results: According to inclusion and exclusion criteria, 30 (76.9%) were in the IgG4− group and 9 (23.1%) were in the IgG4+ group. In the IgG4+ group, the sex ratio of male to female was 2:1 and the mean age was 56.67 ± 13.29 years old. In the IgG4− group, the sex ratio of male to female was 3.29:1 and the mean age was 61.47 ± 12.87 years old. Statistical analysis of the clinical indicators showed significant differences between the two groups in affected eye, preoperative history of glucocorticoids, ocular nerve thickening, the expression of serum IgG4 and prognosis ( P < 0.05). There was no significant statistical difference in laboratory indicators between the two groups, including C3, C4, RF, ASO, CRP, IgA, IgM, IgG, IgG1, IgG2, and IgG3 ( P > 0.05). The event-free cumulative percentages at 3 and 5 years for the 39 lacrimal lymphomas were 81.1 and 62.4%, respectively, with recurrence and death as end events. In 34 lacrimal gland MALT lymphoma cases, the event-free cumulative percentages at 3 and 5 years were 84.4 and 69.1%, respectively. In the IgG4+ and IgG4− groups, the event-free cumulative percentages at 3 years were 75.0 and 87.7%, respectively. The event-free cumulative percentage at 5 years was 62.6% in the IgG4-group and insignificant in the IgG4+ group. There was no statistical difference in event-free cumulative percentage between the two groups ( P = 0.983). Conclusion: The pathogenesis and disease characteristics of IgG4-positive lacrimal lymphoma may differ from IgG4-negative lacrimal lymphoma, but the positive expression of IgG4 may not have significant influence on the recurrence of lacrimal lymphoma.
Controlling intraocular pressure (IOP) remains the mainstay of glaucoma therapy. The trabecular meshwork (TM), the key tissue responsible for aqueous humor (AH) outflow and IOP maintenance, is very sensitive to mechanical forces. However, it is not understood whether Piezo channels, very sensitive mechanosensors, functionally influence AH outflow. Here, we characterize the role of Piezo1 in conventional AH outflow. Immunostaining and western blot analysis showed that Piezo1 is widely expressed by TM. Patch-clamp recordings in TM cells confirmed the activation of Piezo1-derived mechanosensitive currents. Importantly, the antagonist GsMTx4 for mechanosensitive channels significantly decreased steady-state facility, yet activation of Piezo1 by the specific agonist Yoda1 did not lead to a facility change. Furthermore, GsMTx4, but not Yoda1, caused a significant increase in ocular compliance, a measure of the eye's transient response to IOP perturbation. Our findings demonstrate a potential role for Piezo1 in conventional outflow, likely under pathological and rapid transient conditions.
Adenoid cystic carcinoma (ACC) of the lacrimal gland (LGACC) is an aggressive malignant lacrimal gland tumor with a generally poor prognosis. Survival rates for LGACC are 56% at 5 years and 49% at 10 years. Recent studies have indicated that anti-vascular endothelial growth factor (VEGF) therapy can inhibit angiogenesis in ACC cells. This study was designed to explore the efficacy of the antiangiogenic drug bevacizumab in a LGACC patient-derived xenograft (PDX) animal model.The histological structure of PDX was determined by hematoxylin-eosin staining to confirm successful xenografting. Immunohistochemistry (IHC) was used to detect the expression of neovascularization-related genes in LGACC patients and in the PDX model, including VEGF, VEGFR1, and FGFR. In order to compare the efficacy of antiangiogenic drug and traditional chemotherapy drug, PDX models were treated with bevacizumab and cisplatin respectively, and body weight was evaluated. Subsequently, the neovascularization-related proteins VEGF, VEGFR2, and CD34, tumor suppressor P53 and proliferation-related protein Ki67 were analyzed by IHC. Quantitative real-time PCR was employed to examine the mRNA expression of apoptosis-related genes BAD and Caspase 9, and of HIF1α.VEGF, VEGFR1, and FGFR were highly expressed in patients with LGACC and PDX models. Both bevacizumab and cisplatin treatment inhibited PDX tumor growth. The body weight of PDX models treated with cisplatin significantly decreased from day 15, while those treated with bevacizumab did not markedly change. Bevacizumab reduced the expression of VEGF, CD34, and Ki67 in PDX tumors; whereas, bevacizumab upregulated P53 and downregulated HIF1α levels.The present study indicates that antiangiogenic drugs may be a promising treatment strategy for LGACC.
Mertk belongs to the Tyro3, Axl and Mertk (TAM) family of receptor tyrosine kinases, and plays a pivotal role in regulation of cytoskeletal rearrangement during phagocytosis. Phagocytosis by either professional or non-professional phagocytes is impaired in the Mertk deficient individual. In the present study, we further investigated the effects of Mertk mutation on peritoneal macrophage morphology, attachment, spreading and movement. Mertk-mutated macrophages exhibited decreased attachment, weak spreading, loss of spindle-like body shape and lack of clear leading and trailing edges within the first few hours of culture, as observed by environmental scanning electron microscopy. Time-lapse video photography recording showed that macrophage without Mertk conducted mainly random movement with oscillating swing around the cell body, and lost the directional migration action seen on the WT cells. Western blotting showed a decreased phosphorylation of focal adhesion kinase (FAK). Immunocytochemistry revealed that actin filaments and dynamic protein myosin II failed to concentrate in the leading edge of migrating cells. Microtubules were localized mainly in one side of mutant cell body, with no clear MTOC and associated radially-distributed microtubule bundles, which were clearly evident in the WT cells. Our results suggest that Mertk deficiency affects not only phagocytosis but also cell shape and migration, likely through a common regulatory mechanism on cytoskeletons.
We have generated a human induced pluripotent stem cell (iPSC) line derived from urinary cells of a 10years old patient with primary congenital glaucoma (PCG). The cells were reprogrammed with the human OSKM transcription factors using the Sendai-virus delivery system and shown to have full differentiation potential. The line is available and registered in the human pluripotent stem cell registry as BIOi001-A.
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